Two-stroke cycle internal combustion engine with scavenging blower and port control



Aug. 21, 1956 .LKREMsl-:R 2,759,465

TWO-STROKE CYCLE INTERNAL COMBUSTION ENGINE WITH SCAVENGING BLOWER AND PORT CONTROL Filed July 51, 195s JOHANN -KREMSER B7' w ATTORNEYS United States Patent O TWO-STROKE CYCLE INTERNAL COMBUSTION ENGINE WITH SCAVENGING BLOWER AND PORT CONTROL Johann Kremser, Hannover, Germany Application `uly 31, 1953, Serial No. 371,442 8 Claims. (Cl. 123-65) The present invention relates to a two-stroke cycle internal combustion engine with a scavenging blower and port control. So far, in engines of this kind the cast crankcase acted as a scavenging receiver, the crankcase being drawn up to the connecting plane of the cylinder heads. This arrangement required a heavy and complicated casting. The size of the scavenging receiver was limited. Furthermore other engine designs are known which have a separate receiver above the crankcase which extends up to the inlet ports. In this design, too, the size of the scavenging receiver was limited, which caused considerable pressure iiuctuations in the air supply. The unfavourable designs known so far necessitated a high power requirement for the scavenging blower. The application of a centrifugal blower was thus excluded.

It is, therefore, one object of the present invention to eliminate the deficiencies of the designs known so far in that a two-stroke cycle engine with scavenging blower is provided in which the liuid-cooled cylinders are mounted individually on the crankcase, the cylinders having all necessary passages for the transfer of the scavenging air and the exhaust gas, the passages being controlled by the piston; the scavenging receiver being designed as a lightweight housing formed like a hood which encloses that part of the cylinder or cylinders extending above the crankcase.

It is another object of the present invention to provide a two-stroke cycle engine with scavenging blowers in which the housing forming the scavenging receiver is made of two or more parts and may be made of drawn sheet steel, light metal castings, or the like, and may enclose all of the vcylinders of the engine; if desired, it is possible to arrange the cylinders' in groups and to enclose the cylinders belonging to one group by the scavenging receiver.

It is yet another object of the present invention to provide a two-stroke cycle engine with scavenging blowers in which the receiver is separate from the crankcase, as the size of the receiver is not restricted, thus ensuring most favourable pressure and operating conditions for the blower and the design may be laid out so that the different receiver parts are held and sealed by means of the bolts which are provided on the cylinder head in any case.

It is also another object of the present invention to provide a two-stroke cycle engine with scavenging blowers in which the scavenging receiver comprises two parts, the subdivision of these parts being transverse to the cylinder axis and the plane being in the middle of the exhaust pipe; the connection of the exhaust pipe being outside of the scavenging receiver and of cylindrical shape on its outside so that the receiver may be sealed at the exhaust connection in a simple way by means of a ring gasket.

Dilerent embodiments in accordance with this invention are possible. With these and other objects in view which will become apparent in the following detailed description, the present invention will be clearly understood in connection with the accompanying drawings, in which:

Fig. 1 is a sectional elevation of the part of the engine above the crankcase;

Fig. 2 is a top plan view of the device shown in Fig. l, partly in section; and

Fig. 3 is a sectional view of a portion of a cylinder in the region of the exhaust pipe thereof showing a modified form of compressed air housing.

The cylinder 2 is mounted on the crankcase 1. The cooling water jacket of the cylinder in this cas'e is cast en bloc with the cylinder sleeves. The cylinder head 3, containing the combustion chamber 4 and the injection valve 5, is bolted to the cylinder 2 by means of several bolts 6 and nuts 7. Anchor bolts 8 provided with nuts 9 connect the cylinder head and the crankcase 1. Around the anchor bolts 8 the cylinder is provided with correponding pressure sections 20. Rubber gaskets 10 seal the cooling water passage 21 from the crank case 22.

The scavenging receiver is formed by a drawn sheet metal hood 11, 12, the upper housing part 11 being pressed and sealed against the cylinder head 3 by nuts 7. The lower housing part 12, however, is connected with the crankcase 1 by means of the bolts 13, if necessary, using a suitable gasket. Both housing parts 11 and 12 are provided with a flange 24 within the region of the plane 15 and are connected with each other by means of bolts 14 and a gasket 25.

The plane 15 is situated so that it is transverse to the cylinder axis' and in the middle of the exhaust pipe 27. The connecting flange 16 for the exhaust pipe is outside of the scavenging receiver 23 and of cylindrical shape on its outside. The housing parts 11 and 12 have an annular recess within the region of the connecting flange 16 and are sealed by means of a ring gasket 17. In this way assembly and disassembly of the housing parts is very easy.

In the embodiment according to Fig. 3 which shows the cylinder in the region of the exhaust pipe, the cylinder head 3 extends above the scavenging receiver 23. Here the upper housing part 11 is laterally sealed against the cylinder head 3 by means of a gasket 18', i. e. the height of the scavenging receiver is somewhat reduced. The housing parts 11 and 12 have also in this embodiment an annular recess within the region of the con-y necting ange 16 and are sealed by means of a ring gasket 17. In the same manner, as shown in the irst embodiment, the lower housing part 12 is connected with the crank case 1 by means of the bolts 13. The cooling water passage is sealed from the crank case 1 by means of rubber gasket 10.

The scope of this invention is not limited to the various embodiments of the scavenging receiver. Fixing of the housing parts forming the receiver may be accomplished in dilerent ways, as for instance, laterally on the cylinder head, laterally on the cylinder block, between cylinder block and cylinder head, as well as between cylinder block and crankcase, or laterally on the crankcase. Furthermore, this invention may be applied for internal combustion engines with port control as well as for engine with exhaust valve control. The inside of the cylinder is directly connected with the scavenging receiver by means of the scavenging ports 26, and the receiver is directly connected with the scavenging air blower.

While I have disclosed several embodiments of the present invention, it is to be understood that these embodiments are given by example only and not in a limiting sense, the scope of the present invention being determined by the objects and the claims.

I claim:

1. In a two cycle internal combustion engine having a crankcase, individual ported cylinders, having air inlet ports and exhaust ports, each of said cylinders being separately mounted on said crank case, a source of getting compressed air, a compressed air housing for each cylinder comprising a relatively light weight hood partially enclosing the exterior of said cylinders and connected thereto and said crank case in an airtight manner forming a compressed air passage with the exterior of said cylinders, and said air passage being in communication with said air inlet ports of the corresponding cylinders and said air source of compressed air.

2. ln a two cycle internal combustion engine having a crankcase, a ported cylinder having air inlet ports and exhaust ports mounted on the exterior of said crankcase, a source of compressed air, a compressed air housing comprising a relatively light weight housing partially surrounding said cylinder, means connecting said housing to said cylinder and crank case in an airtight manner forming a compressed air passage therebetween and said passage being in communication with said air inlet port of said corresponding cylinder and said air source of compressed air.

3. The two cycle internal combustion engine, as set forth in claim 2, wherein said housing is provided by a plurality of separable sections.

4. The two cycle internal combustion engine, as set forth in claim 2 which includes an exhaust pipe of a cylindrical contiguration, said exhaust pipe being connected to said exhaust port of said cylinder and extending through said housing, said housing having a circular anged opening through which said pipe extends and means sealing said ange around the periphery of said pipe in an airtight manner.

5. The two cycle internal combustion engine, as set forth in claim 2, which includes an exhaust pipe of cylindrical conguration, said exhaust pipe being connected to said exhaust port of said cylinder, said housing is formed by two mating sections whose edges of contact extend laterally of the axis of said cylinder, each of said sections I4 having a flanged semi-circular recess provided in its edge of Contact which anges mate and surround said exhaust pipe in an airtight manner and means for detachably retaining said housing sections together in an airtight manner.

6. In a two cycle internal combustion engine having a crankcase, a ported cylinder having air inlet ports and exhaust ports mounted on the exterior of said crankcase, a source of compressed air, a compressed air housing comprising a hood of sheet material connected at its edges to said cylinder and said crankcase in an airtight manner and spaced from said cylinder providing a compressed air passage from said source of compressed air to the air inlet port of said cylinder.

7. The two cycle internal combustion engine, as set forth in claim 6, wherein said hood is attached at its lower edge to the exterior of said crankcase and at its upper edge to said cylinder with a portion of the head' of said cylinder extending exteriorly of said hood.

8. The two cycle internal combustion engine, as set forth in claim 6, wherein said hood is provided by two mating sections whose edges of contact extend laterally of the axis of said cylinder, each section having an external ange along its edge of contact for mating with the flange of the opposite section and means for detachably retaining said anges together in an airtight manner.

References Cited in the file of this patent UNITED STATES PATENTS 733,665 Lemp July 14, 1903 816,062 Barnett Mar. 27, 1906 1,316,912 Marschall Sept. 23, 1919 1,404,550 Setz Jan. 24, 1922 1,725,121 Wintercorn Aug. 20, 1929 2,066,580 Serverin et al Jan. 5, 19737 2,280,839 Nallinger Apr. 2S, 1942 FOREIGN PATENTS 19,801 Great Britain Sept. 15, 1903 588,658 France Feb. 5, 1925 

